Patent GB-1096225-A (GB)
Title: Improvements in guillotine shearing machines
IPC: B23D35/00
Filed: 1965-03-08
Abstract: 1,096,225. Shearing. CORPET LOUVET ET CIE. March 8, 1965 [March 13, 1964 (2)], No. 9683/65. Heading B3W. In an hydraulically operated guillotine which has fixed blade 2 and a movable blade 6 mounted on a blade carrier 5, the carrier 5 is guided at each end by a slide 7 which is movable to alter the cutting clearance between the blades. Each slide 7 is pivotally mounted at its upper end on a pin 10 which carries a block 12, slidable in an elongated hole 11 in the slide 7. At its lower end the slide 7 is mounted on a pin 13 which has an eccentric mounting shaft 14 rotatable in the side frame of the shear. The eccentrics at each side of the shear are rotated through chain gearing by a common handoperated shaft. The shaft 14 is itself mounted in an eccentric bush 20 which can be locked in any angular position. The range of adjustment provided by the bush 20 is much greater than the range provided by the eccentric shaft 14 and is for the purpose of allowing for the use of cutters of different dimensions. The angle i represents the basic cutting angle between the path of the carrier 5 and the normal to the work which is necessary to obtain a square edge on the work. To maintain this angle when the eccentric bush 20 is adjusted the pivot pin 10 is also provided with an eccentric mounting. The shear angle between the blades, i.e. the angle e in Fig. 5, is adjusted by raising or lowering one end of the blade carrier, and means are provided to link this movement with the eccentric shaft 14, so that when the cutting clearance is adjusted to suit a particular thickness of work, the shear angle is simultaneously adjusted. To achieve this a drum 30 is mounted on the common hand-operated shaft and has one end of a cable 32 attached to it. The cable passes over a guide wheel 33, mounted at one end of the blade carrier, under a guide wheel 34 mounted at the other end of the blade carrier, and at its free end is attached to a counterweight or spring. Secured to the cable is a barrel-shaped cam 36 which operates three limit switches 37, 38 and 39. These three switches control a servo-mechanism which adjusts the position, relative to the frame, of the hydraulic cylinders 25 and 26, Fig. 1 (not shown), which drive the blade downwards. The return stroke of the blade is effected by an hydraulic cylinder 27. When the common hand-operated shaft is rotated to adjust the cutting clearance, the cable 32 is wound on or off the drum and displaces the cam 36. The servo-mechanism then operates until the cam is restored to its original position, relative to the limit switches, and in so doing alters the shear angle between the blades. At each end of the shear is mounted a pair of scrap-cutting blades 53, 54, Fig. 9. The blade 54 is stationary and the blade 53 is attached to the blade carrier 5. The cutting clearance between the blades 53 and 54 is adjusted automatically when the shear angle of the main blades 2 and 6 is altered. To achieve this the blade carrier has mounted thereon a roller 55 which runs in a guide slot 56 in a member secured to the adjacent frame upright. The position of the axis of the roller 56 relative to the blade 53 is such that as the shear angle increases the blade 53 moves away from the blade 54.